diff --git a/packages/vite/src/client.ts b/packages/vite/src/client.ts
index 1821e21d38..6d8ea7e81d 100644
--- a/packages/vite/src/client.ts
+++ b/packages/vite/src/client.ts
@@ -184,7 +184,7 @@ export async function buildClient (ctx: ViteBuildContext) {
   if (clientConfig.server && clientConfig.server.hmr !== false) {
     const serverDefaults: Omit<ServerOptions, 'hmr'> & { hmr: Exclude<ServerOptions['hmr'], boolean> } = {
       hmr: {
-        protocol: ctx.nuxt.options.devServer.https ? 'wss' : 'ws',
+        protocol: ctx.nuxt.options.devServer.https ? 'wss' : undefined,
       },
     }
     if (typeof clientConfig.server.hmr !== 'object' || !clientConfig.server.hmr.server) {